JP7153182B2 - Aggregator and concentrator integrated dehydrator using the same - Google Patents

Description

TECHNICAL FIELD The present invention relates to a flocculating device for producing flocculated sludge by reacting sludge with a flocculant, and a dehydrator integrated with a thickening device using the flocculating device.

Conventionally, in Patent Document 1, in order to improve the dewaterability of the sludge treated by the screw press, a thickener is provided in the front stage of the screw press. A chute for receiving the sludge discharged from the thickener is arranged on the discharge side of the thickener, and the sludge is forced into the screw press by a pressure pump after flowing down the chute. At this time, the sludge, after being added with the inorganic coagulant from the coagulant supply means located on the discharge side of the concentrator, flowed down to the injection pump as it was.

Patent Literature 2 discloses a guide slope for guiding sludge discharged from a gravity thickener to a downstream thickening passage in an auxiliary thickener arranged at the front stage of a screw press.

Patent Literature 3 discloses a plurality of inclined members provided in a sludge supply section at the front stage of a screw press to promote separation of water contained in sludge discharged from a thickener.

Japanese Patent No. 5477373 Japanese Patent No. 4294523 Japanese Patent No. 6091289

In Patent Document 1, sludge discharged from a discharge port provided on the discharge side of a concentrator is guided to a chute connected below the discharge side of the concentrator, and then sent to a screw press by a pressure pump provided in the chute. A flocculant supply means for adding a flocculant to the sludge is provided on the discharge side of the thickener. However, the space from the discharge port of the concentrator to the injection pump is not provided with a device or the like for sufficiently reacting the sludge and the coagulant. Therefore, the sludge discharged from the discharge port drops into the chute without sufficiently reacting with the coagulant after the coagulant is added by the coagulant supply means. There is a problem that the dewaterability of the cake discharged from the screw press deteriorates when the cake is supplied to the screw press in a state in which the aggregation is insufficient.

In Patent Document 2, a flocculant is added to the sludge supplied into the auxiliary thickener from a flocculant spray pipe provided above the auxiliary thickener. Since it is flat, it has little resistance to sludge. Therefore, the sludge flows down in a short period of time without remaining on the guide slope, and is guided to the downstream thickening passage without sufficiently reacting with the coagulant.
The downstream thickening passage is equipped with a screw for reaggregating the sludge and the flocculant while flowing the sludge down to the sludge outlet passage.

In Patent Document 3, a plurality of inclined members are provided in a sludge supply part arranged on the discharge side of a thickener, and the sludge discharged from the thickener is allowed to flow down from the upper inclined member to the lower inclined member in order, and is poured into the sludge. This promotes the separation of contained moisture, but since the surface of the inclined member is flat, the resistance to sludge flowing down the inclined member is small. Therefore, the sludge flows down from the inclined member to the inclined member in a short period of time, and sufficient water separation cannot be performed. Furthermore, since the sludge does not spread in the width direction on the inclined member and the area in contact with the added coagulant becomes small, there is a problem that the sludge and the coagulant flow down without sufficiently reacting.

The present invention has been made in view of the above problems, and by providing an inclined plate with a resistance portion formed below the discharge side of the concentrator, it is possible to prevent the sludge and the coagulant from flowing down with insufficient reaction. To provide a flocculator and a dehydrator integrated with a thickening device using the same, which can prevent sludge dewatering, improve sludge dewatering performance, and reduce the amount of flocculant used.

The present invention relates to a flocculating device provided in a chute connected to a discharge side of a concentrating device having a screw shaft with screw blades wound around a cylindrical outer cylindrical screen mounted on a screw press dewatering machine. A sloped plate extends from the end point located vertically downward from the center of the screw shaft to the diagonally lower right and diagonally lower left, respectively, and makes the sludge flow down in the direction of the slope, and the flow down surface of each slope in the width direction and a coagulant supply means for adding a coagulant to thickened sludge that is provided above each inclined plate and flows down each inclined plate, so that the sludge and the coagulant sufficiently react, The cohesiveness is enhanced , and the strong flocs generated along with the flow down can be supplied to the dehydrator, thereby improving the dehydration performance .

By forming a convex resistance part on the downflow surface of the inclined plate, the sludge flowing down on the inclined plate is dammed by the convex resistance part, the flow speed is reduced, and the sludge for reacting with the flocculant. I can secure enough time. In addition, after the sludge is dammed up, it spreads in the width direction of the inclined plate, thereby increasing the surface area and improving the addition efficiency of the coagulant.
In addition, when a concave resistance portion is formed on the flow-down surface of the inclined plate, the sludge flowing down on the inclined plate flows into the concave resistance portion, thereby reducing the flow speed, and the effect is equivalent to that of the convex resistance portion. is obtained.

By forming the resistance portion by curving the inclined plate in a convex shape, the sludge flowing down on the inclined plate collides with the curved convex resistance portion and is dammed up.
In addition, when the inclined plate is curved in a concave shape to form a resistance portion, the sludge flowing down on the inclined plate flows into the curved concave resistance portion, thereby reducing the flow rate, and the convexly curved resistance portion Equivalent effect is obtained.

By alternately forming the convex resistance portions and the concave resistance portions in the inclination direction of the inclined plate, the flowing sludge is alternately resisted by the convex resistance portions and the concave resistance portions, and the flowing speed is increased. descend.

As described above, in the present invention, resistance is provided to the sludge flowing down by forming the resistance portion on the downward flow surface of the inclined plate. Due to the resistance of the resistance part, the sludge flows down and stays longer on the inclined plate. As a result, sufficient time can be secured for the sludge to react with the flocculant, so that flocculation is enhanced and the amount of flocculant used can be reduced. In addition, the sludge is mixed with the flocculant while flowing down on the inclined plate by its own weight to generate flocculated sludge. can. Since the flocculating device is provided in the rear stage of the thickener and the front stage of the dehydrator, the flocculated sludge in which strong flocs are generated can be supplied to the dehydrator, thereby improving the dehydration performance.

1 is a schematic side view of a concentrator-integrated dehydrator using a flocculating device according to the present invention; FIG. Similarly, it is a schematic front view of a concentrator-integrated dehydrator using a flocculating device. 1 is a perspective view of a main part of a first form of aggregating device according to the present invention; FIG. Similarly, it is a principal part perspective view of the 2nd form of aggregating apparatus. Similarly, it is a principal part perspective view of the 3rd form of aggregating apparatus. Similarly, it is a principal part perspective view of the 4th form of aggregating apparatus. Similarly, it is a principal part perspective view of the 5th form of aggregating apparatus. FIG. 3 is a schematic front view of another embodiment of a concentrator-integrated dehydrator using a flocculating device according to the present invention.

FIG. 1 is a schematic side view of a concentrator-integrated dehydrator using a flocculating device according to the present invention.
The thickener-integrated dehydrator comprises a dehydrator 1, a thickener 2 mounted on the dehydrator 1, a chute 3 connected to the discharge side of the thickener 2 and receiving the sludge discharged from the thickener 2, A press-in pump 4 is provided at the beginning of the dehydrator 1 and presses the sludge received by the chute 3 into the dehydrator 1 . In this embodiment, a screw press is used as the dehydrator 1 . The chute 3 is connected to the suction side of the pressure pump 4 , and the dehydrator 1 is connected to the discharge side of the pressure pump 4 .

The concentrating device 2 has a screw shaft 7 with screw blades 6 wound around a cylindrical outer cylindrical screen 5 , and between the outer cylindrical screen 5 and the outer peripheral surface of the screw shaft 7 , the screw blades 6 form a spiral. It forms a concentration chamber 8 partitioned into. A sludge supply pipe 9 for supplying sludge into the screw shaft 7 is connected to one end of the screw shaft 7, and a driver 10 for differentially rotating the outer cylinder screen 5 and the screw shaft 7 at the other end. is provided. Furthermore, a plurality of supply ports 11 for guiding sludge supplied from the sludge supply pipe 9 into the thickening chamber 8 are provided on the outer peripheral surface of one end of the screw shaft 7, and the sludge is guided to the thickening chamber 8. , the outer cylinder screen 5 and the screw shaft 7 are rotated at different speeds, and flow down to the discharge side of the concentrator 2 . At this time, the filtrate is separated from the outer cylindrical screen 5, and the thickened sludge is discharged from the discharge side of the thickening device 2, flows down into the chute 3, and is pressure-injected into the dehydrator 1 by the pressure-injection pump 4. .

FIG. 2 is a schematic front view of a concentrator-integrated dehydrator using a flocculating device.
A disk-shaped outer cylinder flange 12 is formed on the discharge side of the outer cylinder screen 5 . A plurality of discharge ports 13 are provided along the circumferential direction inside the outer cylinder flange 12 , and the sludge thickened in the thickening chamber 8 is discharged from the discharge ports 13 . Each discharge port 13 has a shape extending in the circumferential direction. Sludge discharged from the discharge port 13 flows down on an inclined plate 14 provided below the outer cylinder flange 12 and above the chute 3 and is guided to the chute 3 . When the sludge flows down on the inclined plate 14, coagulants such as polyiron sulfate are supplied from a plurality of coagulant supply means 15 provided above the inclined plate 14. FIG. In the present embodiment, dripping, spraying, etc. are performed using a known coagulant supply means 15 such as a pipe or nozzle, but the supply method is not particularly limited. Furthermore, the position, number, etc. of the coagulant supply means 15 may be changed as appropriate.

The inclined plate 14 extends obliquely to the lower right and obliquely to the lower left from the end point positioned on the vertical line of the center of the screw shaft 7 . The sludge flow-down surface, which is in the direction of inclination, has a structure in which unevenness is repeated. The convex and concave shapes in the inclined direction are defined as resistance portions 16, and the resistance portions 16 give resistance to the sludge flowing down. By adding resistance to the flowing sludge, the flowing speed of the sludge is reduced, the residence time on the inclined plate 14 is lengthened, and the sludge can be spread in the width direction of the inclined plate 14 to increase the surface area.

FIG. 3 is a perspective view of the essential parts of the first embodiment of the aggregation device according to the present invention.
(a) shows a structure in which convex resistance portions 16 are formed on an inclined plate 14 made of a flat plate at predetermined intervals in the inclined direction and continuously formed in the width direction. In the first form, the cross section of the resistor portion 16 is formed in a rectangular shape.
(b) shows a structure in which convex resistance portions 16 are formed on an inclined plate 14 at predetermined intervals in the inclined direction and discontinuously formed in the width direction. In addition, the cross section of the resistance part 16 is formed in the shape of a mountain.

The convex resistance portions 16 of (a) and (b) serve as resistance to the sludge flowing down and temporarily block the sludge. The dammed sludge has a lower flow rate and a longer residence time on the inclined plate 14, so that sufficient time can be secured for reacting with the flocculant. In addition, after the sludge is dammed up, it spreads in the width direction and the surface area increases, so the addition efficiency of the flocculant is improved. It should be noted that the sludge spread in the width direction of the inclined plate 14 is washed downstream by further sludge flowing down from the rear stage.

In addition, the sludge is mixed with the flocculant while flowing down on the inclined plate 14 by its own weight to generate flocculated sludge. Furthermore, if the resistance portion 16 is detachable from the inclined plate 14, inspection and replacement during maintenance can be facilitated. The resistor portions 16 may be formed in a mountain shape at predetermined intervals in the direction of inclination, and may be formed continuously in the width direction. Alternatively, rectangular ones may be formed at predetermined intervals in the direction of inclination and arranged discontinuously in the direction of width. Furthermore, these may be combined to form a resistance portion, but the present invention is not limited to this.

FIG. 4 is a perspective view of the essential parts of the second embodiment of the aggregation device.
In FIG. 1(a), recessed resistance portions 16 are formed on the downflow surface of an inclined plate 14 made of a flat plate at predetermined intervals in the direction of inclination and are formed continuously in the width direction. In the second form, the cross section of the resistor portion 16 is formed in a rectangular shape.
(b) shows concave resistance portions 16 formed on the downflow surface of the inclined plate 14 at predetermined intervals in the inclined direction and discontinuously formed in the width direction.
In the flocculating device of (a) and (b), the flowing sludge flows into the resistance portion 16 formed in a flat plate, so that the flowing speed is reduced. Note that the resistance portion 16 may be a combination of a rectangle and a chevron, but is not limited to this.

FIG. 5 is a perspective view of the essential parts of the third embodiment of the aggregation device.
(a) is formed by bending a portion of the inclined plate 14 formed of a flat plate into a convex shape across the width direction, and the curved convex resistance portions 16 are formed at predetermined intervals in the inclined direction. .
(b) shows a part of an inclined plate 14 made of a flat plate curved in a concave shape across the width direction, and curved concave resistance portions 16 are formed at predetermined intervals in the inclined direction.

FIG. 6 is a perspective view of the essential part of the fourth embodiment of the aggregation device.
The inclined plate 14 is curved, and convex resistance portions 16 and concave resistance portions 16 are alternately formed in the direction of inclination. In the fourth embodiment, the curved convex resistance portions 16 of (a) and the curved concave resistance portions 16 of (b) in the third embodiment are alternately formed in the direction of inclination. It is curved.

FIG. 7 is a fragmentary perspective view of a fifth embodiment of the aggregation device.
The inclined plate 14 is formed in a zigzag pattern, and convex resistance portions 16 and concave resistance portions 16 are alternately formed in the direction of inclination. When the inclination angle β of the resistance portion 16 is an acute angle of 90 degrees or less, the height a from the apex of the convex resistance portion 16 to the bottom of the concave resistance portion 16 increases.
On the other hand, when the inclination angle β is an obtuse angle larger than 90 degrees and smaller than 180 degrees, the height a is reduced. The cross section of the resistance portion 16 may be a combination of sinusoidal and zigzag shapes, but is not limited to this. In addition, the thickness, angle of inclination β, length in the direction of inclination and width, the positions of the end points, etc. of the inclined plate 14 can be appropriately changed according to the specifications and the properties of the sludge.

FIG. 8 is a schematic front view of another embodiment of a concentrator-integrated dehydrator using a flocculating device according to the present invention.
A chute 3 for receiving the sludge discharged from the discharge port 13 is connected to the discharge side of the concentrator 2 . A plurality of inclined plates 14 and a plurality of coagulant supply means 15 are provided on the side wall inside the chute 3 . An inclined plate 14 provided on one side wall is installed so as to descend toward the other side wall. Similarly, the inclined plate 14 provided on the other side wall is installed so as to descend toward the one side wall. The sludge supplied into the chute 3 flows down alternately on the inclined plates 14 and then flows downward by alternately placing the sludge downwards.
In the sludge flowing down on the inclined plate 14, since the water flowing speed is higher than the solid content flowing speed, the water and solid content are separated by this speed difference. At this time, the resistance portion 16 of the inclined plate 14 gives resistance to the flowing sludge, thereby decreasing the flowing speed, lengthening the residence time on the inclined plate 14, and improving the cohesiveness.

The coagulant supply means 15 is arranged facing the inclined plate 14 . Specifically, with respect to the inclined plate 14 arranged on one side wall, the coagulant supply means 15 is arranged on the other side wall, and with respect to the inclined plate 14 arranged on the other side wall, one inclined plate A coagulant supply means 15 is arranged at 14 . By arranging it so as to face the inclined plates 14, it becomes possible to supply the flocculant to the sludge flowing down while jumping on the plurality of inclined plates 14 provided on the side wall. Sludge sufficiently reacts with the flocculating agent on the inclined plate 14 and flows downward, forming firm flocs. As a result, it is possible to prevent the breakage of the flock due to the impact when it is dropped.
In this embodiment, the flocculating device is applied to a concentrator-integrated dehydrator. Application to a mechanism for flowing down sludge such as is also possible. In addition, application to known concentrators such as belt concentrators and gravity concentrators as concentrators, and application to known dehydrators such as belt presses, filter presses, vacuum dehydrators and centrifugal dehydrators as dehydrators. is also possible.

Since the flocculating apparatus according to the present invention can generate flocculated sludge while sludge is flowing down, it can be easily applied to existing treatment flows. In addition, since the structure of the apparatus is simple and space-saving, it can be easily applied to the latter stage of the concentrator or the former stage of the dehydrator. The coagulator adds a coagulant to the sludge and can be applied to all equipment (dehydrator, etc.) that uses the coagulated sludge. Sludge can be stably treated in this process. In addition, since the flocculation device utilizes the weight of the sludge itself, there is no need to provide a new device or the like that requires power in order to improve the flocculation of the sludge.

14 Inclined plate 16 Resistor 15 Coagulant supply means 1 Dehydrator 2 Concentrator 3 Chute

Claims (6)

It was placed on a screw press dehydrator (1) and connected to the discharge side of a concentrating device (2) having a screw shaft (7) wound with screw blades (6) inside a cylindrical outer cylinder screen (5). In the agglomerating device provided in the chute (3),
An inclined plate (14) extends from an end point positioned vertically downward from the center of the screw shaft (7) of the concentrator (2) to an oblique lower right and oblique lower left, respectively, to allow the sludge to flow down in the inclined direction. When,
a resistance portion (16) formed in the width direction on the downflow surface of each inclined plate (14);
flocculant supply means (15) provided above each inclined plate (14) for adding a flocculant to thickened sludge flowing down each inclined plate (14) ;
A flocculation device comprising: 2. A flocculation device according to claim 1, characterized in that a convex resistance portion (16) is formed on the downflow surface of said inclined plate (14). 3. A coagulator according to claim 1 or 2, characterized in that a concave resistance portion (16) is formed on the downflow surface of said inclined plate (14). 2. Agglomerating device according to claim 1, characterized in that the inclined plate (14) is convexly curved to form a resistance portion (16). 5. Aggregator according to claim 1 or 4, characterized in that the inclined plate (14) is concavely curved to form a resistance portion (16). 6. A coagulator according to claim 3 or 5, characterized in that convex resistance portions (16) and concave resistance portions (16) are alternately formed in the inclination direction of said inclined plate (14).

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